ABSTRACT
Patients seeking alternatives to hormone replacement are increasingly using non-prescription phytoestrogen supplements. The potential of these herbal remedies to prevent bone loss, heart disease, menopausal symptoms or breast cancer has been a focus of attention in scientific and lay literature. It is important to understand the effects of phytoestrogens, particularly whether excess exposure can promote hyperplasia or neoplasia of breast tissue. We report the case of a man diagnosed with breast cancer whose history was notable for extensive use of supplemental phytoestrogens and the absence of family history of breast cancer or BRCA1/BRCA2 mutation. In conclusion, breast tissue effects of phytoestrogens remain unclear. The increasing popularity and availability of phytoestrogen dietary supplements necessitates additional research in order to counsel patients regarding their safety and efficacy.